The volume of blow molded jugs, such as of the one gallon size, in which milk and similar beverages are commonly distributed in retail stores are often regulated by forming depressions in the jug side walls extending into the volume defined by the container material. Such depressions are molded into the container side wall by locating removable inserts within the mold. Depending upon the size of the depression desired an appropriate mold insert is mounted within the mold cavity, and such inserts are installed and removed manually, a time consuming and troublesome operation.
Also, depending on the nature of the beverage to be contained, and the bottling temperature thereof, it may be required that no volume regulating depression be formed in the jug side wall, and it is necessary to stop container production and modify the mold by the addition and removal of inserts to produce the container form desired.
It is an object of the invention to provide a mold for blow molding containers of synthetic plastic material wherein the mold cavity side wall includes adjustable inserts for forming volume regulating depressions within the molded container.
A further object of the invention is to provide a mold for blow molding synthetic plastic containers wherein removable depression forming inserts mounted in the mold cavity side wall are readily adjustable and include means for locking the insert relative to the mold side wall.
An additional object of the invention is to provide an adjustable insert for molds utilized in blow molding containers wherein the volume of the insert located within the mold cavity is readily and accurately adjustable exteriorly of the mold, and wherein the insert configuration is such as to avoid weakening the formed container.
In the practice of the invention a recess is formed in the side wall of a mold employed to blow mold synthetic plastic containers, such as one gallon jugs used in the retail packaging of milk. An insert member is movably mounted within this recess, and in the two embodiments illustrated, the insert member may have a longitudinal screw adjusted movement, or may consist of a rotatable member of noncircular cross-sectional configuration. The insert member is either longitudinally or rotatably adjustable within its mold side wall recess wherein a variable mass of the insert is adjustably positioned within the mold cavity resulting in a depression defined in the side wall of the molded container.
Locking means are associated with the insert member whereby the relative adjusted position of the member to the mold will be maintained during successive cycles, and as the insert member is exteriorly adjusted variations in the volume of the depressions formed in the molded container by the insert may be readily produced.
The insert may be of such configuration as to conform to the normal shape of the mold cavity wherein no insert portion is located within the cavity and the molded container is free of volume adjusting depressions.